Turbomachine Fluid-Conduit Housing Coupling System and Method

ABSTRACT

A shroud portion of a fluid-conduit housing provides for concentrically shrouding a portion of bladed rotor operatively coupled to a rotor shaft rotationally supported by at least one bearing operatively coupled to the centerbody. An internal cylindrical surface at an end of the fluid-conduit housing mates with a corresponding external cylindrical surface on a corresponding side of the centerbody. The fluid-conduit housing is operatively coupled to the centerbody with a plurality of radial pins, wherein each radial pin slideably engages with at least one of a corresponding radial bore in the fluid-conduit housing or a corresponding radial bore in the centerbody so as to provide for substantially maintaining the concentricity of the shroud portion of the fluid-conduit housing relative to the bladed rotor regardless of a thermal expansion of the fluid-conduit housing relative to the centerbody.

CROSS-REFERENCE TO RELATED APPLICATIONS

The instant application claims the benefit of prior U.S. ProvisionalApplication Ser. No. 61/501,891 filed on 28 Jun. 2011, which isincorporated by reference herein in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 illustrates an isometric view of a first aspect of an internalcombustion engine comprising a pair of cylinder heads and acorresponding pair of turbocharger cores integrated therewith;

FIG. 2 illustrates an isometric view of a cylinder head and turbochargercore from the first aspect of an internal combustion engine illustratedin FIG. 1;

FIG. 3 illustrates first cross-sectional view through the cylinder headand turbocharger core illustrated in FIG. 2;

FIG. 4 illustrates an isometric view of the turbocharger core as used inthe embodiments illustrated in FIGS. 1-3;

FIG. 5 illustrates an isometric view of a nozzle cartridge assembly fromthe turbocharger core illustrated in FIG. 2;

FIG. 6 illustrates a second cross-sectional view through the cylinderhead and turbocharger core illustrated in FIG. 2;

FIG. 7 illustrates a transverse cross-sectional view through a turbinenozzle portion of the turbocharger core illustrated in FIG. 4;

FIG. 8 illustrates a transverse cross-sectional view through a bearinghousing portion of the turbocharger core illustrated in FIG. 4;

FIG. 9 illustrates third cross-sectional view through the cylinder headand turbocharger core illustrated in FIG. 2;

FIG. 10 illustrates an expanded view of a portion of the thirdcross-sectional view through the cylinder head and turbocharger coreillustrated in FIG. 9;

FIG. 11 illustrates a schematic view of a first alternative embodimentof an interface of a plurality of exhaust runners from each of aplurality of cylinders with a cavity in a cylinder head adapted toreceive a turbocharger core;

FIG. 12 illustrates a schematic view of a second alternative embodimentof an interface of a plurality of exhaust runners from each of aplurality of cylinders with a cavity in a cylinder head adapted toreceive a turbocharger core;

FIG. 13 illustrates an isometric view of a portion of a second aspect ofan internal combustion engine incorporating a first embodiment of afirst aspect of a turbocharger assembly operatively coupled to anassociated exhaust manifold;

FIG. 14 illustrates an exploded view of portions of the first embodimentof the first aspect of the turbocharger assembly and associated housingused with the second aspect of the internal combustion engineillustrated in FIG. 13;

FIG. 15 illustrates a longitudinal cross-sectional exploded view of thefirst embodiment of the first aspect of the turbocharger assembly andassociated housing used with the second aspect of the internalcombustion engine illustrated in FIG. 13;

FIG. 16 illustrates a fragmentary longitudinal cross-sectional view of asecond embodiment of the first aspect of a turbocharger assembly inaccordance with the second aspect an internal combustion engine;

FIG. 17 illustrates a transverse cross-sectional view of the secondembodiment of the first aspect of the turbocharger assembly illustratedin FIG. 16;

FIG. 18 illustrates a third embodiment of the first aspect of aturbocharger assembly incorporating a second aspect of an associatedturbocharger core having an associated radial-flow turbine, inaccordance with the second aspect of an internal combustion engine;

FIG. 19 illustrates an isometric partially exploded view of a firstembodiment of a second aspect of a turbocharger assembly useable withthe second aspect an internal combustion engine, illustrating a firstembodiment of associated radial pins that provide for coupling theassociated exhaust housing to the associated centerbody, and thatprovide for maintaining a concentricity the exhaust housing relative tothe centerbody of the turbocharger assembly;

FIG. 20 illustrates a portion of a longitudinal cross-section of thefirst embodiment of a second aspect of a turbocharger assemblyillustrated in FIG. 19, illustrating a corresponding turbine portion inrelation to the corresponding centerbody portion;

FIG. 21 illustrates an aft-looking radial cross-section of the firstembodiment of the second aspect of a turbocharger assembly illustratedin FIGS. 19 and 20 through a transverse plane intersecting the centersof a plurality of associated radial pins;

FIG. 22 illustrates a fragmentary longitudinal cross-section of thefirst embodiment of the second aspect of a turbocharger assemblyillustrated in FIGS. 19-21, illustrating a first embodiment of anassociated seal between the centerbody and exhaust housing of theturbocharger assembly;

FIGS. 23 a and 23 b schematically illustrate a thermal expansion of aninternal cylindrical surface of an exhaust housing relative to anexternal cylindrical surface of a centerbody, illustrating the pluralityof associate radial pins maintaining the relative concentricity of theinternal and external cylindrical surfaces for two different conditionsof relative thermal expansion;

FIG. 24 illustrates a forward-looking radial cross-section of a secondembodiment of the second aspect of a turbocharger assembly similar tothat illustrated in FIG. 19, through a transverse plane intersecting thecenters of a plurality of associated radial pins, for a secondembodiment of the radial pins;

FIG. 25 illustrates a fragmentary longitudinal cross-section of a thirdembodiment of the second aspect of a turbocharger assembly similar tothat illustrated in FIG. 19, illustrating a second embodiment of theassociated seal between the centerbody and exhaust housing of theturbocharger assembly;

FIG. 26 illustrates a fragmentary longitudinal cross-section of a fourthembodiment of the second aspect of a turbocharger assembly similar tothat illustrated in FIG. 19, illustrating a third embodiment of theassociated seal between the centerbody and exhaust housing of theturbocharger assembly;

FIG. 27 illustrates a fragmentary longitudinal cross-section of a fifthembodiment of the second aspect of a turbocharger assembly similar tothat illustrated in FIG. 19, illustrating a fourth embodiment of theassociated seal between the centerbody and exhaust housing of theturbocharger assembly; and

FIG. 28 illustrates a fragmentary longitudinal cross-section of a sixthembodiment of the second aspect of a turbocharger assembly, illustratinga second aspect of an associated volute portion of the exhaust housingof the turbocharger assembly.

DESCRIPTION OF EMBODIMENT(S)

Referring to FIG. 1, a pair of turbocharger cores 10 are integrated witha corresponding pair of cylinder head assemblies 12 of a first aspect ofan internal combustion engine 14, 14.1 of a V-type configuration, forexample, a V-6 internal combustion engine 14, 14.1′. For example, theinternal combustion engine 14, 14.1 can be any of a variety of designsoperating on one or more of a variety of types of fuels, including butnot limited to gasoline, diesel, bio-diesel, natural gas, including LNGand CNG, propane including LP gas, ethanol or methanol, in accordancewith any one of a variety of thermodynamic cycles, including, but notlimited to, for example, the Otto cycle, the Diesel cycle, the Atkinsoncycle, the Miller cycle or a two-stroke cycle. Referring also to FIGS.2-10, each turbocharger core 10 comprises a compressor 16 driven by anexhaust-powered turbine 18, wherein when the turbocharger core 10 isattached to the internal combustion engine 14, 14.1, for example,through an intercooler, each associated turbine 18 is inserted in andcooperates with a cavity 20, for example, a cylindrical cavity 20′ or avolute cavity 20″, in the corresponding cylinder head assembly 12adapted to receive exhaust gases 21 from the associated cylinder orcylinders 22 associated therewith via associated exhaust runners 24. Forexample, the turbocharger core 10 incorporates an axial-flow turbine 18,which can be configured with a relatively low associated moment ofinertia so as to provide for a relatively rapid dynamic response tochanges in the associated operating condition of the internal combustionengine 14, 14.1. In the first aspect of the internal combustion engine14, 14.1, the exhaust runners 24 from each cylinder 22 communicate witha common first exhaust port 26 in the side of the cavity 20 at alocation off-axis relative to the central axis 28 of the cavity 20 so asto induce a circulation of the exhaust gases 21 flowing thereinto.

The turbocharger core 10 comprises a turbine rotor 30 of a turbochargerrotor assembly 31 operatively coupled to an aft end 32.1 of a rotorshaft 32 of the turbocharger rotor assembly 31 that is rotationallysupported by rotor shaft support assembly 33, also known as a centerbody33, comprising an aft journal bearing 34 and a forward rolling elementbearing 36 located within an associated bearing housing 38 and spacedapart from one another along the rotor shaft 32. The bearing housing 38incorporates a cooling jacket 40 therewithin in fluid communication withinlet 42 and outlet 44 ports that are adapted to receive a flow ofcooling water from the water cooling system 46 of the internalcombustion engine 14, 14.1 and thereby provide for cooling the aftjournal bearing 34 and the forward rolling element bearing 36, whereinone set of inlet 42 and outlet 44 ports is used for one side of theinternal combustion engine 14, 14.1, and the other one set of inlet 42′and outlet 44′ ports is used for the other side of the internalcombustion engine 14, 14.1, with the unused set of inlet 42′, 42 andoutlet 44′, 44 ports on either side being plugged. An oil inlet port 48is adapted to receive a supply of pressurized engine oil from an oilpump of the internal combustion engine 14, 14.1 and distribute this oilto the aft journal bearing 34 and the forward rolling element bearing 36via associated oil distribution passages 50. Oil draining from aftjournal bearing 34 and the forward rolling element bearing 36 is gravitycollected in an oil scavenge cavity 52 within the base of the bearinghousing 38, and is returned to the internal combustion engine 14, 14.1via an associated oil scavenge line 54 (illustrated in FIG. 13)connected to an associated oil scavenge port 54′ at the base of thebearing housing 38.

It should be understood that the rotor shaft support assembly 33 is notlimited to the combination of an aft journal bearing 34 and a forwardrolling element bearing 36, but the rotor shaft support assembly 33could alternatively comprise any combination of journal and rollingelement bearings, or conceivably a single extended-length journalbearing.

The compressor 16 of the turbocharger core 10 comprises a compressorrotor 56 of the turbocharger rotor assembly 31 operatively coupled tothe forward end 32.2 of the rotor shaft 32 and adapted to rotatetherewith about a central axis 28′ of the turbocharger core 10, which issubstantially aligned with the central axis 28 of the cavity 20. Forexample, in one embodiment, the compressor rotor 56—in accordance withwhat is known as a boreless hub,—incorporates an aftward extendinginternally threaded boss 58 that threads onto the forward end 32.2 ofthe rotor shaft 32, and the turbine rotor 30 is welded to the aft end32.1 of the rotor shaft 32 along the periphery of a cavity 60 betweenthe forward end of the turbine rotor 30 and the aft end 32.1 of therotor shaft 32 that provides for reducing heat transfer from the turbinerotor 30 to the rotor shaft 32. The forward rolling element bearing 36comprises an outer race 62 and forward 64 and aft 66 inner races locatedon the rotor shaft 32 between a shoulder 32.3 and the compressor rotor56, which provides for positioning the rotor shaft 32 within the bearinghousing 38. The bearing housing 38 incorporates forward 70 and aft 72seals that provide for preventing leakage of oil from the bearinghousing 38 into either the turbine 18 or compressor 16 of theturbocharger core 10.

Referring to FIGS. 4, 5 6 and 8-10, the turbocharger core 10 furthercomprises a turbine nozzle cartridge assembly 74 operatively coupled tothe aft side 38.1 of the bearing housing 38. The turbine nozzlecartridge assembly 74 comprises a forward nozzle wall 76, an aft nozzlewall 78 aftwardly separated therefrom, a plurality of vanes 80 disposedbetween the forward 76 and aft 78 nozzle walls, a turbine rotor shroudportion 82 extending aftward from the aft nozzle wall 78, and a nozzleexhaust portion 84 extending aftward from the throat portion 82.Although the nozzle exhaust portion 84 is illustrated with a relativelyexpanded diameter so as to provide for at least partially diffusing theassociated exhaust gases, the nozzle exhaust portion 84 need notnecessarily be relatively expanded in diameter relative to theassociated turbine rotor shroud portion 82.

For example, in one embodiment, the forward nozzle wall 76 is formed asa first sheet metal element and the combination of the aft nozzle wall78 and turbine rotor shroud 82 and nozzle exhaust 84 portions is formedas a second sheet metal element,—for example, each by stamping orspinning;—and the vanes 80 are each formed from sheet metal—, forexample, by stamping,—and inserted in and then welded or brazed to aplurality of corresponding slots 86 in each of the forward 76 and aft 78nozzle walls. In another embodiment, the aft nozzle wall 78, the turbinerotor shroud portion 82 and the nozzle exhaust portion 84 are eachformed from two or more separate sheet metal pieces that that are thenjoined together, for example, by welding, brazing and/or bypress-fitting. Alternatively, the turbine nozzle cartridge assembly 74may be cast or sintered, for example, laser sintered. The turbine nozzlecartridge assembly 74 is constructed of a material that can withstandhigh temperature exhaust gases 21, for example, of a nickel alloy, forexample, stainless steel with a relatively high nickel content, forexample, 310 stainless steel, that provides for high temperatureoxidation resistance and strength. The remainder of the turbochargercore 10—being either water- or oil-cooled,—can be constructed of lessexotic and more economical materials, such as aluminum or cast iron. Forexample, in addition to the water-cooled bearing housing 38, thecylinder head assembly 12 may be adapted with water cooling passages inthermal communication with the exhaust housing portion 88 thereof so asto provide using relatively low-cost materials, such as aluminum, forthe construction thereof. Accordingly, the separate turbine nozzlecartridge assembly 74 of the turbocharger core 10 provides for anoverall more economical use of high-temperature-tolerant materials—forexample, limited to the turbine nozzle cartridge assembly 74—than wouldotherwise be possible, and also provides for integrating theturbocharger core 10 into the cylinder head assembly 12. For example,the combined amount of raw material needed to make the turbine nozzlecartridge assembly 74 and the relatively more simple associated exhausthousing portion 88 of the cylinder head assembly 12 would be less thanthe amount of material needed to make an equivalent conventionalturbocharger exhaust housing.

In yet another embodiment, the turbine rotor shroud portion 82 of theturbine nozzle cartridge assembly 74 is reinforced with a containmentsleeve 90 that provides for containing the turbine rotor 30 in the eventof a failure of the associated turbine blades 92 thereof.

The turbine nozzle cartridge assembly 74 extends through the cavity 20,20′, 20″ in the cylinder head assembly 12. In operation, exhaust gases21 from the cylinder or cylinders 22 flow through the associated exhaustrunners 24 into the first exhaust port 26, i.e. a cavity inlet exhaustport 26, leading into the cavity 20, 20′, 20″, wherein the off-axislocation of the first exhaust port 26 relative to the cavity 20, 20′,20″ causes a swirl of the exhaust gases 21 flowing within the cavity 20,20′, 20″. The exhaust gases 21 then flow with swirl into the peripheralinlet 93 of the turbine nozzle cartridge assembly 74 along the vanes 80thereof, and against the turbine blades 92 of the turbine rotor 30,thereby driving the turbine rotor 30 that in turn rotates the rotorshaft 32 and the compressor rotor 56 attached thereto. The exhaust gases21 then flow through the nozzle exhaust portion 84 of the turbine nozzlecartridge assembly 74 before being exhausted into and through a secondexhaust port 94, i.e. a cavity outlet exhaust port 94, that extends froma counterbore 96 in the aft end 20.1 of the cavity 20, 20′, 20″, whereinthe second exhaust port 94 is connected to the engine exhaust system 98,which, for example, may include one or more exhaust treatment devices100, for example, one or more catalytic converters or mufflers. Thecylinder head assembly 12 can incorporate a wastegate valve 99 operativebetween an exhaust runner 24 and the second exhaust port 94 so as toprovide for bypassing exhaust gases 21 directly to the engine exhaustsystem 98 without first flowing through the turbine nozzle cartridgeassembly 74 and associated turbine rotor 30. Accordingly, the forward 76and aft 78 nozzle walls of the turbine nozzle cartridge assembly 74redirect and accelerate the circumferentially swirling exhaust gases21—flowing within the cavity 20, 20′, 20″ outside of the turbine nozzlecartridge assembly 74—radially inward and axially aftward, and theresulting axially-aftward-flowing swirling exhaust gases 21 then impingeupon the turbine blades 92 of the turbine rotor 30, thereby driving theturbine rotor 30, wherein in one embodiment, the associated vanes 80 incooperation with the forward 76 and aft 78 nozzle walls are adapted toprovide for the proper vector orientation of the impinging exhaust gases21 relative to the turbine rotor 30 so as to maximize the efficiency ofthe turbine 18.

The aft end 84.1 of the nozzle exhaust portion 84 of the turbine nozzlecartridge assembly 74 incorporates an external sealing surface 102 thatcooperates with a seal ring 104—for example, a piston-ring-type sealring 104″—located in an internal groove 106 in the counterbore 96 so asto provide for sealing the discharge end 108 of the turbine nozzlecartridge assembly 74 to the exhaust housing portion 88 of the cylinderhead assembly 12 so that substantially all of the exhaust gases 21 aredischarged from the turbine nozzle cartridge assembly 74 into andthrough the second exhaust port 94 and into the associated engineexhaust system 98, thereby substantially isolating the exhaust gases 21in the cavity 20, 20′, 20″ upstream of the turbine nozzle cartridgeassembly 74 from the exhaust gases 21 discharged from the turbine nozzlecartridge assembly 74. The seal ring 104 in cooperation with theexternal sealing surface 102 provides for enabling discharge end 108 ofthe turbine nozzle cartridge assembly 74 to both slide in an axialdirection and expand or contract in a radial direction, responsive tothermally-induced expansion or contraction thereof, while maintainingthe sealing condition at the discharge end 108 of the turbine nozzlecartridge assembly 74, without substantial associated thermally-inducedloading of the turbine nozzle cartridge assembly 74.

The forward end 76.2 of the forward nozzle wall 76 comprises acylindrical lip 110 that fits over a corresponding cylindrical step 112that extends aftwardly from the aft side 38.1 of the bearing housing 38.The turbine nozzle cartridge assembly 74 is retained on the bearinghousing 38 by a plurality of radial pins 114 that extend throughcorresponding radial holes 116 in the cylindrical lip 110 and intocorresponding blind radial holes 118 in the cylindrical step 112. Theradial pins 114 and associated radial holes 116, 118 are locatedsymmetrically around the circumferences of the cylindrical lip 110 andthe cylindrical step 112. The inside diameter of the cylindrical lip 110and the outside diameter of the cylindrical step 112 may be adapted sothat at ambient temperature, the cylindrical lip 110 has an interferencefit with the cylindrical step 112. However, at elevated operatingtemperatures, the forward nozzle wall 76 and associated cylindrical lip110 are free to thermally expand relative to cylindrical step 112responsive to differences in temperature or thermal expansion rates ofthe forward nozzle wall 76 and bearing housing 38, respectively, inwhich case, the engagement of the cylindrical lip 110 by the radial pins114 provides for retaining the turbine nozzle cartridge assembly 74 tothe bearing housing 38, and the symmetric arrangement of the associatedradial pins 114 and associated radial holes 116, 118 provides forkeeping the turbine nozzle cartridge assembly 74 substantiallyconcentric with the central axis 28″ of the turbocharger core 10 overthe thermal operating range thereof. For example, during normaloperation, the turbine nozzle cartridge assembly 74 would heat uprelatively more quickly, and to a substantially higher temperature, thanthe bearing housing 38, and as a result the inside diameter of thecylindrical lip 110 would typically expand so as to be greater than theoutside diameter of the cylindrical step 112, so as to transition from apossible interference at ambient temperature to a substantially loosefit at elevated temperatures, under which circumstances, the radial pins114 would provide for symmetrically and concentrically retaining thecylindrical lip 110 on the cylindrical step 112, so as to preserve therelative alignment of the turbine nozzle cartridge assembly 74 with theassociated turbine rotor 30.

Alternatively, the forward end 76.2 of the forward nozzle wall 76 can becentered on the bearing housing 38 with a plurality ofaftwardly-extending axial pins or bolts extending from the aft side 38.1of the bearing housing 38 through corresponding radial slots in theforward end 76.2 of the forward nozzle wall 76, and retained on thebearing housing 38 either by the bolts or by a step in the forward endof the cavity 20.

When the turbine nozzle cartridge assembly 74 is assembled to thebearing housing 38, the turbine blades 92 of the turbine rotor 30 arelocated within the turbine rotor shroud portion 82 of the turbine nozzlecartridge assembly 74, which turbine rotor shroud portion 82 accordinglyfunctions as a turbine tip shroud 82′, wherein the inside diameter ofthe turbine tip shroud 82′ is adapted to provide for about 0.01 inch oftip clearance 212 to the tips 120 of the turbine blades 92, whichrelatively tight tolerance provides for improved efficiency of theturbine 18 that might otherwise be possible had the clearance beenlarger. Accordingly, with the turbine tip shroud 82′ a part the turbinenozzle cartridge assembly 74 that is retained on the bearing housing 38and free to float within the counterbore 96 in the cavity 20, 20′, 20″,the turbine tip shroud 82′ is unaffected by the exhaust housing portion88 of the cylinder head assembly 12, for example, by thermally-inducedstresses therein or therefrom, or external mechanical loads thereto,that might otherwise result in interference with the tip 120 of theturbine blades 92, so that a relatively small clearance between theturbine tip shroud 82′ and the tip 120 of the turbine blades 92 can bereadily realized using production hardware and processes.

The turbocharger core 10 is assembled to the cylinder head assembly 12with a plurality of bolts 122 through a corresponding plurality of holes124 in an associated flange 126 or set of flanges 126′ of or extendingfrom the bearing housing 38, through an adapter bushing 128, and intocorresponding threaded holes 130 in the forward portion 132 of theexhaust housing portion 88 of cylinder head assembly 12 around theperiphery of the of the cavity 20, 20′, 20″, so that when mounted to thecylinder head assembly 12, the bearing housing 38 of the turbochargercore 10 provides for closing the forward end of the cavity 20, which issealed at the junction of the bearing housing 38 and adapter bushing 128and the junction of the adapter bushing 128 and the forward portion 132of the exhaust housing portion 88 of cylinder head assembly 12 aroundthe periphery of the of the cavity 20, 20′, 20″ for example, either bymating flat surfaces—as illustrated—or by mating conical surfaces. Theinside diameter of the adapter bushing 128 is sufficiently greater thatthe outside diameter of the cylindrical lip 110 of the forward nozzlewall 76 of the turbine nozzle cartridge assembly 74 so as to provide foruninhibited thermally induced expansion of the cylindrical lip 110within the gap 134 therebetween, so as to prevent a thermally-inducedmechanical stress of the turbine nozzle cartridge assembly 74 that wouldotherwise occur if the outward radial expansion of the cylindrical lip110 were otherwise restrained by the adapter bushing 128. The adapterbushing 128 also provides for capturing the radial pins 114 within theirradial holes 118 in the cylindrical step 112. The aft surface 136 of theadapter bushing 128 is located and shaped so as to provide for arelatively smooth transition from the inside surface 138 of the cavity20′, 20″ to the forward nozzle wall 76 so as to facilitate the flow ofexhaust gases 21 from the cavity 20′, 20″ into the turbine nozzlecartridge assembly 74. For example, in one embodiment, the aft surface136 of the adapter bushing 128 comprises a portion of a concave toroidalsurface 136 that in cross-section provides for a quarter-round filletbetween the inside surface 138 and the forward nozzle wall 76.Alternatively, the adapter bushing 128 can be replaced by incorporatingthe material thereof directly into the exhaust housing portion 88 of thecylinder head assembly 12. Furthermore, alternatively, the turbochargercore 10 may be mounted to the forward portion 132 of the exhaust housingportion 88 of cylinder head assembly 12 with a V-clamp rather than bolts122.

In operation of the turbocharger core 10, exhaust gases 21 from thefirst exhaust port 26 are first collected in the annulus 140 defined byportion of the cavity 20, 20′, 20″ of the exhaust housing portion 88 ofthe cylinder head assembly 12 on the outside of the turbine nozzlecartridge assembly 74, and then accelerated therefrom by the turbinenozzle cartridge assembly 74 into the turbine blades 92 of the turbinerotor 30. The turbine nozzle cartridge assembly 74 provides fordirecting and accelerating exhaust flow into the turbine blades 92 ofthe turbine rotor 30, and controlling the associated mass flow of theseexhaust gases 21. Accordingly, the turbine nozzle cartridge assembly 74can be configured—independent of the design of the cavity 20, 20′, 20″or the associated exhaust housing portion 88 of the cylinder headassembly 12, for example, by adjusting the area/radius ratio (A/R) ofthe passage 140 through the turbine nozzle cartridge assembly 74—so asto adapt to the particular turbocharging requirements of a giveninternal combustion engine 14, 14.1, which provides for simplifying theprocess of tuning the turbocharger core 10 to the internal combustionengine 14, 14.1 because the only component to be changed in that processwould be the turbine nozzle cartridge assembly 74. For example, in oneset of embodiments, the forward 76 and aft 78 nozzle walls comprisecorresponding forward 76′ and aft 78′ curved swept surfaces, the shapesof which may be adapted in cooperation with the associated vanes 80 toprovide for tuning the turbocharger core 10.

Responsive to exhaust gases 21 impinging thereupon, the turbine rotor 30of the turbine 18 of the turbocharger core 10 drives the rotor shaft 32that rotates in the aft journal bearing 34 and forward rolling elementbearing 36 in the bearing housing 38 and in turn drives the compressorrotor 56 that rotates within an associated compressor housing 142 of theassociated compressor 16, which provides for compressing air from acentral inlet 144 to the compressor housing 142, and discharging thecompressed air through a volute diffuser 146 surrounding the compressorrotor 56. The compressed air is discharged from the compressor 16 into aconduit 148 that is coupled to an inlet plenum 150, for example, coupledto or surrounding a throttle body 152 coupled to an inlet manifold 154of the internal combustion engine 14, 14.1.

Referring to FIGS. 11 and 12, in accordance with respective first andsecond alternative embodiments, the cavity 20, 20′, 20″ of the exhausthousing portion 88 of the cylinder head assembly 12 may be configured toreceive exhaust gases 21 from a plurality of first exhaust ports 26,26.1, 26.2, 26.3, each operatively associated with one or moreassociated exhaust runners 24, 24.1, 24.2, 24.3, each exhaust runner 24operatively associated with one or more cylinders 22 of the internalcombustion engine 14, 14.1, wherein for each first exhaust port 26,26.1, 26.2, 26.3, each corresponding associated exhaust runner 24, 24.1,24.2, 24.3 is oriented so as to introduce exhaust gases 21 substantiallytangentially into the cavity 20, 20′, 20″ so that the resulting flow ofexhaust gases 21 in the cavity 20, 20′, 20″ from each associated firstexhaust port 26, 26.1, 26.2, 26.3 swirls in a common swirl direction156. For example, referring to FIG. 11, in the first alternativeembodiment, the cavity 20, 20′, 20″ is coupled to each of threedifferent cylinders with three different exhaust runners 24, 24.1, 24.2,24.3, each of which discharges exhaust gases 21 into the cavity 20, 20′,20″ through a separate, corresponding first exhaust port 26, 26.1, 26.2,26.3, wherein the associated exhaust runners 24, 24.1, 24.2, 24.3 areoriented so that all of the first exhaust port 26, 26.1, 26.2, 26.3discharge exhaust gases 21 tangentially into the cavity 20, 20′, 20″ ina common swirl direction 156. Furthermore, referring to FIG. 12, in thesecond alternative embodiment, the cavity 20, 20′, 20″ is coupled toeach of three different cylinders with three different exhaust runners24, 24.1, 24.2, 24.3, two of which exhaust runners 24, 24.1, 24.2discharge exhaust gases 21 into the cavity 20, 20′, 20″ throughseparate, corresponding first exhaust port 26, 26.1, 26.2, the third ofwhich exhaust runners 24, 24.3 discharges exhaust gases 21 into thesecond exhaust runner 24, 24.2, which in turn discharges the exhaustgases 21 into the cavity 20, 20′, 20″ through the second of theplurality of first exhaust ports 26, 26.2, wherein the associatedexhaust runners 24, 24.1, 24.2 are oriented so that both the first 26,26.1 and second 26, 26.2 exhaust ports discharge exhaust gases 21tangentially into the cavity 20, 20, 20 in a common swirl direction 156.

By incorporating the turbocharger core 10 in the associated cylinderhead assembly 12, and providing for water-cooling the bearing housing 38and the associated exhaust housing portion 88 of the cylinder headassembly 12 that surrounds the associated cavity 20, 20′, 20″ of theturbocharger core 10, the turbocharger core 10 provides for reducing theamount of high-temperature tolerant material, for example a relativelyhigh nickel content alloy, than would otherwise be required for acorresponding comparable stand-alone turbocharger assembly, whichprovides for reducing cost in comparison with a stand-alone turbochargerassembly. Furthermore, the incorporation of the turbocharger core 10 inthe associated cylinder head assembly 12 provides for more closelycoupling the exhaust from the cylinders 22 of the internal combustionengine 14, 14.1 to the turbocharger core 10, which provides for improvedefficiency than would otherwise be possible with a correspondingcomparable stand-alone turbocharger assembly.

Referring to FIGS. 13-15, in accordance with a second aspect of aninternal combustion engine and a first embodiment of an associated firstaspect of a turbocharger assembly 200.1′, the associated turbochargercore 10 cooperates with a separate turbocharger exhaust housing 158, aninlet 160 of which is operatively coupled to the exhaust manifold 162 ofan internal combustion engine 14, 14.2, for example, with a plurality ofbolts 164 through a first flange 166 at the outlet 168 of the exhaustmanifold 162 into a second flange 170 at the inlet 160 of theturbocharger exhaust housing 158. The inlet 160 is in fluidcommunication with a cavity 20″ in the turbocharger exhaust housing 158via a first exhaust port 26′ located so as to direct associated exhaustgases 21 off-center of the so as to induce a swirling flow of exhaustgases 21 therein. The bearing housing 38 of the turbocharger core 10,with the turbine nozzle cartridge assembly 74 attached thereto asdescribed hereinabove, is bolted to a peripheral face 172 of theturbocharger exhaust housing 158 surrounding the cavity 20″ with aplurality of bolts 174 through the bearing housing 38 and intoassociated threaded sockets 176 on the turbocharger exhaust housing 158around the peripheral face 172, so that the associated turbine nozzlecartridge assembly 74 extends through the cavity 20″ and into anassociated second exhaust port 94′ on the opposite side of the cavity20″. The second exhaust port 94′ incorporates a seal ring 104 in aninternal groove 106 that cooperates with the associated external sealingsurface 102 on the aft end 84.1 of the nozzle exhaust portion 84 of theturbine nozzle cartridge assembly 74, so as to provide for sealing thedischarge end 108 of the turbine nozzle cartridge assembly 74 to theturbocharger exhaust housing 158 so that substantially all of theexhaust gases 21 are discharged from the turbine nozzle cartridgeassembly 74 into and through the second exhaust port 94 and into theassociated engine exhaust system 98, thereby substantially isolating theexhaust gases 21 in the cavity 20″ upstream of the turbine nozzlecartridge assembly 74 from the exhaust gases 21 discharged from theturbine nozzle cartridge assembly 74. The seal ring 104 in cooperationwith the external sealing surface 102 provides for enabling dischargeend 108 of the turbine nozzle cartridge assembly 74 to both slide in anaxial direction and expand or contract in a radial direction, responsiveto thermally-induced expansion or contraction thereof, while maintainingthe sealing condition at the discharge end 108 of the turbine nozzlecartridge assembly 74, without substantial associated thermally-inducedloading of the turbine nozzle cartridge assembly 74.

In operation, exhaust gases 21 from the exhaust manifold 162 flow intothe inlet 160 of the turbocharger exhaust housing 158 and then into theassociated cavity 20″. The exhaust gases 21 swirl about the outside ofthe turbine nozzle cartridge assembly 74 within the cavity 20″, and thenflow with swirl into the peripheral inlet 93 of the turbine nozzlecartridge assembly 74 along the vanes 80 thereof, and against theturbine blades 92 of the turbine rotor 30, thereby driving the turbinerotor 30 that in turn rotates the rotor shaft 32 and the compressorrotor 56 attached thereto. The exhaust gases 21 then flow through thenozzle exhaust portion 84 of the turbine nozzle cartridge assembly 74before being exhausted into and through the second exhaust port 94′ inthe turbocharger exhaust housing 158, and then into the engine exhaustsystem 98, which, for example, may include one or more exhaust treatmentdevices 100, for example, one or more catalytic converters or mufflers.

The turbocharger exhaust housing 158 could be constructed of the sametype of material, for example cast iron, or alternatively, cast with arelatively-high-nickel-content alloy, as could be used for the exhaustmanifold 162. As for the first aspect of an internal combustion engine,the turbocharger core 10 may be tuned to a particular engine bymodifying the turbine nozzle cartridge assembly 74, independently of thedesign of the turbocharger exhaust housing 158 and the associated cavity20″.

Referring to FIGS. 16 and 17, in accordance with a second embodiment ofan associated first aspect of a turbocharger assembly 200.1′ adapted foruse with the second aspect of an internal combustion engine 14, 14.2,the associated turbocharger exhaust housing 158 incorporates an internalheat shield 178, for example, constructed from a sheet-metal materialthat can withstand high temperature exhaust gases 21, for example, of anickel alloy, for example, stainless steel with a relatively high nickelcontent, for example, 310 stainless steel, that provides for hightemperature oxidation resistance and strength. Exhaust gases 21 withinthe turbocharger exhaust housing 158 are substantially contained withinthe inside surface 178.1 of the internal heat shield 178, the latter ofwhich incorporates a plurality externally-protruding dimples 180 thatprovide for separating the outside surface 178.2 of the internal heatshield 178 from the inside surface 158′ of the turbocharger exhausthousing 158 with an associated air gap 182 that provides for reducingconductive heat transfer from the internal heat shield 178 to theturbocharger exhaust housing 158. Accordingly, the internal heat shield178 provides for both radiative and conductive heat shielding.

Although the internal heat shield 178 is illustrated in the context of asecond aspect of the internal combustion engine 14, 14.2, i.e. externalof an associated cylinder head assembly 12, an internal heat shield 178can be particularly beneficial in the context of the first aspect theinternal combustion engine 14, 14.1, i.e. integrated with an associatedcylinder head assembly 12, so as to provide for substantially reducingthe amount of heat transferred from the exhaust gases 21 to the cylinderhead assembly 12 that would otherwise need to be removed by theassociated water cooling system 46 of the internal combustion engine 14,14.1. For example, in one simulated embodiment of the first aspect ofthe internal combustion engine 14, 14.1 with an associated aluminumcylinder head assembly 12 incorporating a cavity 20 having a 6 mm wallthickness and lined with a 1.5 mm thick internal heat shield 178 incooperation with an associated turbocharger core 10, for exhaust gases21 at 1050 degrees Celsius, the associated heat transfer was reducedfrom 8.20 Kilowatts to 1.80 Kilowatts, and the associated heat transfercoefficient was reduced from about 9 Watts per degree Kelvin to about 2Watts per degree Kelvin, with the internal heat shield 178 operating atabout 904 degrees Celsius.

The turbocharger core 10 has been illustrated hereinabove configuredwith an axial-flow turbine 18′, wherein the exhaust gases 21 dischargedfrom a nozzle portion 74.1 of the turbine nozzle cartridge assembly 74are directed in a substantially axial-aftwards direction 184 aftwardonto and against the turbine blades 92 of the associated axial-flowturbine 18′ located aftward of the forward nozzle wall 76, vanes 80, andnozzle portion 74.1 of the turbine nozzle cartridge assembly 74.

Alternatively, referring to FIG. 18, a third embodiment of the firstaspect of a turbocharger assembly 200.1″ adapted in accordance with thesecond aspect of an internal combustion engine is illustratedincorporating a second aspect of an associated turbocharger core 10′having an associated radial-flow turbine 18″ and a correspondingassociated turbine nozzle cartridge assembly 74′ that provides fordischarging the associated exhaust gases 21 in a substantiallyradial-inwards direction 186 from the nozzle portion 74.1′ of theturbine nozzle cartridge assembly 74 onto and against the turbine blades92′ of the associated radial-flow turbine 18″ located radially inboardof the forward nozzle wall 76, vanes 80, and nozzle portion 74.1′ of theturbine nozzle cartridge assembly 74′.

Furthermore, alternatively, the turbocharger core 10 may be adapted witha mixed-flow turbine, i.e. a combined radial-flow and axial-flowturbine, with an associated turbine nozzle cartridge assembly 74 adaptedto cooperate therewith, but otherwise generally configured as describedhereinabove, with the associated mixed-flow turbine rotor located aftand radially inboard of the forward nozzle wall 76, vanes 80, and nozzleportion 74.1 of the turbine nozzle cartridge assembly 74, with anassociated conical boundary therebetween.

Furthermore, it should be understood that either the first or secondaspects of the associated internal combustion engine 14, 14.1, 14.2described hereinabove may be adapted to provide for a wastegate valve 99to provide for bypassing exhaust gases 21 from the internal combustionengine 14, 14.1, 14.2 around the turbocharger core 10, i.e. to as toenable some or all of the exhaust gases 21 to flow from the exhaustrunners 24 or exhaust manifold 162 to the engine exhaust system 98without flowing through the turbine 18.

The turbine nozzle cartridge assembly 74 provides for readily matchingor tuning the turbocharger core 10 to a particular internal combustionengine 14, 14.1, 14.2, because other components of the turbocharger core10—particularly the associated exhaust housing portion 88 of thecylinder head assembly 12 or the associated turbocharger exhaust housing158—would not typically need to be modified during that process.Furthermore, with the turbine nozzle cartridge assembly 74 separate fromand free to float relative to the associated exhaust housing portion 88of the cylinder head assembly 12 or the associated turbocharger exhausthousing 158, production versions of the turbocharger core 10 can beadapted to work with relatively smaller clearances between the turbinetip shroud 82 and the tips 120 of the turbine blades 92 without dangerof interference therebetween during the operation of the turbochargercore 10 over the life thereof.

Referring to FIGS. 19-22, a first embodiment of an associated secondaspect, a turbocharger assembly 200.2 ^(i) usable in cooperation with asecond aspect of an internal combustion engine 14, 14.2 comprises acenterbody 33, a compressor 16 and a turbine 18.

The centerbody 33 comprises a bearing housing 38, at least one bearing34, 36 within and operatively coupled to the bearing housing 38, and arotor shaft 32 rotationally supported by the at least one bearing 34. 36spaced therealong, wherein the rotor shaft 32 is part of an associatedturbocharger rotor assembly 31.

The compressor 16 of the turbocharger core 10 comprises a compressorrotor 56—also part of the turbocharger rotor assembly 31—within anassociated compressor housing 142 that is operatively coupled to aforward side 33.2 of the centerbody 33. The compressor rotor 56 isoperatively coupled to the forward end 32.2 of the rotor shaft 32 andadapted to rotate therewith about an axis of rotation 202′ of theturbocharger rotor assembly 31.

The turbine 18 comprises a turbine rotor 30—also part of theturbocharger rotor assembly 31—within an associated turbocharger exhausthousing 158 that is operatively coupled to an aft side 33.1 of thecenterbody 33. The turbine rotor 30 is operatively coupled to—forexample, welded to—the aft end 32.1 of the rotor shaft 32 along theperiphery of a cavity 60 between the forward end of the turbine rotor 30and the aft end 32.1 of the rotor shaft 32 that provides for reducingheat transfer from the turbine rotor 30 to the rotor shaft 32. An inlet160 of the turbocharger exhaust housing 158 provides for operativelycoupling to, and receiving exhaust gases 21 from, an exhaust manifold162 of an internal combustion engine 14, 14.2. For example, asillustrated in FIG. 13, the inlet 160 of the turbocharger exhausthousing 158 is operatively coupled to the exhaust manifold 162 with aplurality of bolts 164 through a first flange 166 at the outlet 168 ofthe exhaust manifold 162 into a second flange 170 at the inlet 160 ofthe turbocharger exhaust housing 158. The inlet 160 is in fluidcommunication with a first aspect of a volute 204 ^(i) in a first aspectof a volute portion 204 ^(i)′ of the turbocharger exhaust housing 158that provides for discharging exhaust gases 21 onto the turbine rotor30. At least a portion of an aft boundary 206 ^(i) of the volute portion204 ^(i)′ comprises a surface of revolution 206 ^(i)′ about the axis ofrotation 202 of the turbine rotor 30. The aft boundary 206 ^(i) islocated further from the centerbody 33 than a corresponding opposingforward boundary 207 ^(i) of the volute portion 204 ^(i)′. For example,in one embodiment the surface of revolution 206 ^(i)′ comprises a planarsurface 206 ^(i)″ that is substantially perpendicular to the axis ofrotation 202′. The exhaust gases 21 are discharged from the outlet 208of the volute 204 ^(i) onto the turbine rotor 30 so as to provide fordriving the turbine rotor 30, which in turn drives the associatedturbocharger rotor assembly 31.

A portion of the turbine rotor 30 is concentrically surrounded by ashroud portion 210 of the turbocharger exhaust housing 158, wherein theradius of the shroud portion 210 of the turbocharger exhaust housing 158exceeds that of the corresponding radius of the turbine rotor 30 by acorresponding tip clearance 212. The efficiency of the turbine 18 isgenerally improved with decreasing tip clearance 212 as a result of acorresponding associated reduction in exhaust gases 21 bypassing theturbine blades 92, 92′ through the annular region between the tips 120of the turbine blades 92, 92′ and the shroud portion 210 of theturbocharger exhaust housing 158. Upon discharge from the turbine rotor30, the exhaust gases 21 are then discharged through an exhaust outlet214 at an aft end 158.1 of the turbocharger exhaust housing 158 and intothe associated engine exhaust system 98. Accordingly, the turbochargerexhaust housing 158 comprises a corresponding fluid conduit 216 betweenthe inlet 160 and the outlet 208 thereof, through which the exhaustgases 21 flow, and within which the associated turbine rotor 30operates.

A forward end 158.2 of the turbocharger exhaust housing 158 incorporatesan internal cylindrical surface 218 that mates with a correspondingexternal cylindrical surface 220 on the aft side 33.1 of the centerbody33. An axis 202″ of the external cylindrical surface 220 issubstantially concentric with an axis of rotation 202′ of the turbinerotor 30 and with an axis 202 of the internal cylindrical surface 218.

The turbocharger exhaust housing 158 is operatively coupled to thecenterbody 33 with a plurality of radial pins 222, each of which extendsradially across a junction 224 between the internal 218 and external 220cylindrical surfaces and engages both the centerbody 33 and a wall 226of the turbocharger exhaust housing 158 so as to prevent more thaninsubstantial relative axial movement therebetween. Each radial pin 222is slideably engaged with at least one of a corresponding radial bore228 in the turbocharger exhaust housing 158 and a corresponding radialbore 228 in the centerbody 33 so that the internal cylindrical surface218 is free to thermally expand radially relative to the externalcylindrical surface 220. The radial bore 228 in the turbocharger exhausthousing 158 is closed to the fluid conduit 216. The plurality of radialpins 222 are arranged around the centerbody 33 so as to provide for theinternal 218 and external 220 cylindrical surfaces to remainsubstantially concentric regardless of a thermal expansion of theturbocharger exhaust housing 158 relative to the centerbody 33, and soas to provide for the shroud portion 210 of the turbocharger exhausthousing 158 to remain substantially concentric regardless of a thermalexpansion of the turbocharger exhaust housing 158 relative to theturbine rotor 30. For example, as illustrated in FIG. 22, for one set ofembodiment, the diameter 230 of the internal cylindrical surface 218 isless than the diameter 232 of the external cylindrical surface 220 atroom temperature so as to provide for an interference fit therebetweenin a non-operative state of the turbocharger assembly 200.2 ^(i). Byincorporating the plurality of radial pins 222 in cooperation with thecorresponding plurality of radialbores 228 to provide for a radialthermal expansion of the turbocharger exhaust housing 158 relative tothe centerbody 33 that is substantially without constraint other than asto the maintenance of concentricity of the internal 218 and external 220cylindrical surfaces, the second aspect of the turbocharger assembly200.2 provides for configuring the diameter of the shroud portion 210 ofthe turbocharger exhaust housing 158 in relation to that of the turbinerotor 30 so to provide for an associated tip clearance 212 at roomtemperature that is less than 4 percent of the radius of the turbinerotor 30 at the aft portion thereof.

For example, the plurality of radial pins 222 may be eithersymmetrically located or equi-spaced—or both—around the junction 224between the centerbody 33 and around the associated turbocharger exhausthousing 158. For example, FIG. 21 illustrates a plurality of six radialpins 222 that are equi-spaced from one another and are in a symmetricalarrangement with respect to one another. Generally, the plurality ofradial pins 222 would comprise at least three radial pins 222.

In operation of the turbocharger assembly 200.2 ^(i), exhaust gases 21from the exhaust manifold 162 flow into the inlet 160 of theturbocharger exhaust housing 158, through the associated volute 204^(i), and then discharge from the outlet 208 thereof onto the turbineblades 92, 92′ of the turbine rotor 30, thereby driving the turbinerotor 30 that in turn rotates the rotor shaft 32 and the compressorrotor 56 attached thereto. The exhaust gases 21 then flow through theshroud portion 210 of the turbocharger exhaust housing 158 before beingexhausted through the associated exhaust outlet 214, and then into theengine exhaust system 98, which, for example, may include one or moreexhaust treatment devices 100, for example, one or more catalyticconverters or mufflers. The turbocharger exhaust housing 158 could beconstructed of the same type of material, for example cast iron, oralternatively, cast with a relatively-high-nickel-content alloy, ascould be used for the exhaust manifold 162 of the internal combustionengine 14, 14.2. The exhaust gases 21 heat the turbocharger exhausthousing 158 upon flowing through the associated fluid conduit 216thereof, thereby causing the turbocharger exhaust housing 158 tothermally expand relative to the centerbody 33, thereby causing a gap234 between the internal 218 and external 220 cylindrical surfaces, thelatter of which remain substantially concentric as a result of theconstraining action of the radial pins 222 spaced around the junction224 therebetween, which slide within the corresponding associated radialbores 228, as illustrated in FIGS. 23 a and 23 b for relatively lessthermal expansion and relatively more thermal expansion, respectively.

For example, in accordance with the first embodiment of an associatedsecond aspect of the turbocharger assembly 200.2 ^(i) illustrated inFIGS. 19-22, each radial pin 222 is slideably engaged with both a firstradial bore 228.1 in the centerbody 33, and a second radial bore 228.2in the wall 226 of the turbocharger exhaust housing 158, so that eachradial pin 222 can slide relative to either or both the first 228.1 orsecond 228.2 radial bores responsive to a thermal expansion of theturbocharger exhaust housing 158 relative to the centerbody 33.Alternatively, for at least one or all of the radial pins 222, theradial pin 222 could be radially restrained in one of the centerbody 33and wall 226 of the turbocharger exhaust housing 158, but slideablyengaged with a corresponding radial bore 228 in the other of thecenterbody 33 and wall 226 of the turbocharger exhaust housing 158. Forexample, alternatively, the radial pin 222 could be installed with aninterference fit in the first radial bore 228.1 in the centerbody 33,but slideably engaged in the second radial bore 228.2 in the wall 226 ofthe turbocharger exhaust housing 158, or the radial pin 222 could beinstalled with an interference fit in the second radial bore 228.2 inthe wall 226 of the turbocharger exhaust housing 158, but slideablyengaged in the first radial bore 228.1 in the centerbody 33, so as toprovide for retaining the radial pin 222 in the turbocharger assembly200.2 ^(i).

Yet further alternatively, referring to FIG. 24, in accordance with asecond embodiment of the second aspect of a turbocharger assembly 200.2^(ii) that incorporates a second embodiment of associated radial pins222′, each radial pins 222′ incorporates a threaded end portion 236 thatengages a corresponding internal thread 238 in the centerbody 33extending radially inwards from a corresponding radial counterbore228.1′ in the centerbody 33, the latter of which engages the body 239 ofthe radial pin 222′ so as to provide for rotationally aligning theradial counterbores 228.1′ in the centerbody 33 with the correspondingsecond radial bores 228.2 in the wall 226 of the turbocharger exhausthousing 158, which in cooperation with the radial pins 222′ provides forsubstantially centering the internal 218 and external 220 cylindricalsurfaces with respect to one another, while the radial pin 222′ isretained to the centerbody 33 by engagement of the threaded end portion236 with the internal thread 238 in the centerbody 33, wherein the headportions 240 of the radial pins 222′ are adapted to provide forinstalling the radial pins 222′ during assembly of the turbochargerassembly 200.2 ^(ii).

Alternatively, one or more radial pins 222 could be threaded near thecorresponding head portion 240 so as to provide for engaging acorresponding threaded, counterbored portion radially outwards of acorresponding second radial bore 228.2 in the wall 226 of theturbocharger exhaust housing 158, wherein the body 239 of the radial pin222 then is slideably engaged with the first 228.1 and second 228.2radial bores for purposes of assembly, and slideably engaged with thefirst radial bore 228.1 in the centerbody 33 during operation of theturbocharger assembly 200.2 ^(ii) so as to provide for substantiallycentering the internal 218 and external 220 cylindrical surfaces withrespect to one another regardless of thermal expansion of theturbocharger exhaust housing 158 relative to the centerbody 33.

In accordance with the first embodiment of the associated second aspectof the turbocharger assembly 200.2 ^(i) illustrated in FIGS. 19-22, eachradial pin 222 is slideably engaged with both the first 228.1 and second228.2 radial bores at least during assembly, but is retained to theturbocharger assembly 200.2 ^(i) either by a weld 242 to theturbocharger exhaust housing 158, or by staking a radially outboardportion 244 of the second radial bore 228.2 in the wall 226 of theturbocharger exhaust housing 158, either with the radial pin 222extending therethrough as illustrated, or, alternatively, with arelatively shorter radial pin 222 that is inserted radially within theradially outboard portion 244.

The first embodiment of the associated second aspect of the turbochargerassembly 200.2 ^(i) further incorporates a seal 246 operative betweenthe centerbody 33 and an end face 248 of the turbocharger exhausthousing 158—for example, optionally operative within a groove 250 in theend face 248 of the turbocharger exhaust housing 158—that provides forpreventing the exhaust gases 21 from escaping the turbocharger exhausthousing 158 from gaps 234, 252 between the turbocharger exhaust housing158 and the centerbody 33, wherein the seal 246 is configured so as toprovide for accommodating thermal expansion or contraction of theturbocharger exhaust housing 158 relative to the centerbody 33. Forexample, the seal 246 may comprise either a thermal gasket 254—forexample, as illustrated in FIGS. 20 and 22 for the first embodiment ofthe associated second aspect of the turbocharger assembly 200.2 ^(i), ora metallic seal 256, for example, comprising a radial cross-sectionselected from the group consisting of a V-shaped cross-section 258 and afirst aspect of a C-shaped cross-section 260′, for example, asillustrated in FIGS. 25 and 26, respectively for the third and fourthembodiments of the associated second aspect of the turbocharger assembly200.2 ^(iii), 200.2 ^(iv), respectively, wherein the associated seals246 are operative across an axial gap 252. In one set of embodiments,for example, as illustrated in FIGS. 20, 22, 25 and 26, the externalcylindrical surface 220 is stepped into a corresponding side 33.1 of thecenterbody 33, and the seal 246 is operative between the end face 248and a radial surface 262 extending radially outwards from the externalcylindrical surface 220 stepped into the corresponding side 33.1 of thecenterbody 33, wherein the V-shaped cross-section 258 and the firstaspect of the C-shaped cross-section 260 metallic seals 256 haveassociated sealing surfaces and are oriented so that these sealingsurfaces are axially spring-biased respectively against the associatedradial surface 262 of the centerbody 33 and the associated end face 248of the turbocharger exhaust housing 158 so as to provide for sealing thegap 252 therebetween while also providing for a radial movement of theend face 248 relative to the radial surface 262 responsive to a thermalexpansion or contraction of the of the turbocharger exhaust housing 158relative to the centerbody 33.

Referring to FIG. 27 a fifth embodiment of the second aspect of aturbocharger assembly 200.2 ^(v) the seal 246 is operative across aradial gap 234 between the centerbody 33 and the turbocharger exhausthousing 158, for example, by incorporating a metallic seal 256incorporating a second aspect of a C-shaped cross-section 260″ that isoriented so that the associated sealing surfaces are radiallyspring-biased respectively against an the external cylindrical surface220 of the centerbody 33 and an associated internal cylindrical surface263 of an associated counterbore 265 at the forward end 158.2 of theturbocharger exhaust housing 158 so as to provide for sealing theassociated radial gap 234′ therebetween regardless of a radial movementof the end face 248 relative to the radial surface 262 responsive to athermal expansion or contraction of the of the turbocharger exhausthousing 158 relative to the centerbody 33.

In accordance with one set of embodiments, the plurality of radial bores228 are match-drilled through the wall 226 and internal cylindricalsurface 218 of the turbocharger exhaust housing 158, through theexternal cylindrical surface 220 of the centerbody 33, and into thecenterbody 33 after fully sliding the internal cylindrical surface 218of the turbocharger exhaust housing 158 onto the external cylindricalsurface 220 of the centerbody 33 with sufficient force to compress theseal 246 sufficiently enough to provide for sealing the end face 248 ofthe turbocharger exhaust housing 158 against the corresponding radialsurface 262 of the centerbody 33 under all subsequent anticipatedoperating conditions for the design life of the turbocharger assembly200.2.

Referring to FIG. 20, the use of the plurality of radial pins 222 incooperation with the corresponding plurality of associated radial bores228 to operatively couple the turbocharger exhaust housing 158 to thecenterbody 33—for example, rather than a V-clamp as might be used in aconventional turbocharger—provides for locating the associated volute204 ^(i) forward of an aft boundary 206 ^(i) of an outlet 208 thereofonto the bladed rotor 30 so as to provide for a direction of flow 264 ofthe exhaust gases 21 onto the bladed rotor 30 that is eithersubstantially radially inwards or at least partially axially aftwardfrom the centerbody 33 with decreasing distance from the bladed rotor30.

In another set of embodiments, also illustrated in FIGS. 20 and 21, aheat shield 266 is operative between the centerbody 33 and the turbinerotor 30 within an axial bore 268 in the turbocharger exhaust housing158, wherein the axial bore 268 has a diameter in excess of a maximumdiameter of the turbine rotor 30 so as to provide for assembling theturbocharger exhaust housing 158 over the turbine rotor 30, the latterof which is preassembled as part of the centerbody 33. An outer rim 270of the heat shield 266 is retained axially between the centerbody 33 andthe turbocharger exhaust housing 158, and is keyed to the centerbody 33with an axial pin 272 extending therefrom through a corresponding axialhole 274 through the outer rim 270 of the heat shield 266—so as toprevent a rotation of the heat shield 266—and, in one embodiment, intoan axial bore 276 in a corresponding forward portion 278 of theturbocharger exhaust housing 158 so as to provide for roughly aligningthe turbocharger exhaust housing 158 with the centerbody 33 duringassembly, wherein the radial clearance around the axial pin 272 withinthe axial bore 276 in the corresponding forward portion 278 of theturbocharger exhaust housing 158 is sufficient so as to not interferewith a thermal expansion of the internal cylindrical surface 218 of theturbocharger exhaust housing 158 relative to the centerbody 33.

Referring to FIG. 28 a sixth embodiment of the second aspect of aturbocharger assembly 200.2 ^(vi) incorporates a second aspect of avolute 204 ^(ii) and associated second aspect of the volute portion 204^(i)′ of the turbocharger exhaust housing 158—but is otherwise similarto the first aspect of the turbocharger assembly 200.2 ^(i) describedhereinabove—wherein at least a portion of a forward boundary 207 ^(ii)of the volute portion 204 ^(i)′ comprises a surface of revolution 207^(ii)′ about the axis of rotation 202 of the turbine rotor 30. Acorresponding opposing aft boundary 206 ^(ii) is located further fromthe centerbody 33 than the forward boundary 207 ^(ii) of the voluteportion 204 ^(ii)′. For example, in one embodiment the surface ofrevolution 207 ^(ii)′ comprises a planar surface 207 ^(i)″ that issubstantially perpendicular to the axis of rotation 202. The exhaustgases 21 are discharged from the outlet 208 of the volute 204 ^(i) ontothe turbine rotor 30 so as to provide for driving the turbine rotor 30,which in turn drives the associated turbocharger rotor assembly 31.

Although not illustrated in the drawings, it should be understood thatthe compressor housing 142 of the associated compressor 16 of theturbocharger assembly 200.2 could also be operatively coupled to thecenterbody 33 with a plurality of radial pins 222 in cooperation with acorresponding plurality of associated radial bores 228 similarly asdescribed hereinabove for the turbine 18 of the turbocharger assembly200.2.

Furthermore, it should also be understood that the arrangement of theplurality of radial pins 114, 222 in cooperation with a correspondingplurality of associated radial bores 116, 118, 228 similarly asdescribed hereinabove for the turbine 18 of the turbocharger assembly200.2 can be used in other types of turbomachines, for example,superchargers, turbines, pumps, or compressors, so as to provide formaintaining the concentricity of an associated fluid-conduit housing 74,74′, 142, 158 with respect to a centerbody 33 so as to provide forprovide for maintaining the concentricity of a shroud portion 82, 82′,210 of the fluid-conduit housing 74, 74′, 142, 158 with respect to acorresponding bladed rotor 30, 56 regardless of a thermal expansion ofthe fluid-conduit housing 74, 74′, 142, 158 with respect to thecenterbody 33, wherein the term fluid is intended to include gases,vapors and liquids, and the associated fluid 21 flows either entirelywithin the associated fluid-conduit housing 142, 158, or within thefluid-conduit housing 74, 74′ that in turn is operative within anotherfluid-conduit housing 20, 20′, 20″, 142, 158.

A turbomachine apparatus comprises a centerbody 33, at least one bladedrotor 30, 56 and at least one fluid-conduit housing 74, 74′, 142, 158 incooperation therewith.

Although, for purposes of illustration, the reference signs referred tohereinbelow are associated with the turbocharger embodiments illustratedherein, it should be understood that the term turbomachine is notlimited to a turbocharger. The centerbody 33 comprises a bearing housing38, at least one bearing 34, 36 within and operatively coupled to thebearing housing 38; and a rotor shaft 32 rotationally supported by theat least one bearing 34, 36 spaced along the rotor shaft 32. The atleast one bladed rotor 30, 56 is operatively coupled to the rotor shaft32 supported by the centerbody 33. Each bladed rotor 30, 56 is operativewithin a corresponding fluid conduit 216 defined by the fluid-conduithousing 74, 74′, 142, 158. The at least one fluid-conduit housing 74,74′, 142, 158 incorporates an inlet 144, 160 to provide for receiving acorresponding fluid 21 within the fluid conduit 216 that provides foreither driving or being driven, pumped or compressed by a correspondingbladed rotor 30, 56 responsive to an interaction of the correspondingfluid 21 with a plurality of blades 92, 92′ of the bladed rotor 30, 56.The at least one fluid-conduit housing 74, 74′, 142, 158 comprises aninternal cylindrical surface 110, 218 at an end 158.2 thereof that mateswith a corresponding external cylindrical surface 112, 220 on acorresponding side 33.1 of the centerbody 33. An axis 202″ of theexternal cylindrical surface 112, 220 is substantially concentric withan axis of rotation 202′ of the bladed rotor 30, 56 and with an axis 202of the internal cylindrical surface 110, 218. The fluid-conduit housing74, 74′, 142, 158 is operatively coupled to the centerbody 33 with aplurality of radial pins 114, 222, so that the internal cylindricalsurface 110, 218 is free to thermally expand relative to the externalcylindrical surface 112, 220, each radial pin 114, 222 of the pluralityof radial pins 114, 222 being slideably engaged with at least one of acorresponding radial bore 116, 228, 228.2 in the fluid-conduit housing74, 74′, 142, 158 and a corresponding radial bore 118, 228, 228.1 in thecenterbody 33. In one set of embodiments, the radial bore 228, 228.2 inthe fluid-conduit housing 142, 158 is closed to the fluid conduit 216.Each the radial pin 114, 222 is oriented radially with respect to boththe internal cylindrical surface 110, 218 and the external cylindricalsurface 112, 220. The plurality of radial pins 114, 222 are arrangedaround the centerbody 33 so as to provide for the internal 110, 218 andexternal 112, 220 cylindrical surfaces to remain substantiallyconcentric regardless of a thermal expansion of the fluid-conduithousing 74, 74′, 142, 158 relative to the centerbody 33, and at least aportion of the fluid-conduit housing 74, 74′, 142, 158 comprises ashroud portion 82, 82′, 210 that substantially concentrically surroundsa portion of the bladed rotor 30, 56.

Regarding the relative size of the internal 110, 218 and external 112,220 cylindrical surfaces, in one set of embodiments, the internal 110,218 and external 112, 220 cylindrical surfaces are mated with aninterference fit at room temperature.

Regarding the plurality and location of the radial pins 114, 222, theplurality of radial pins 114, 222 are either substantially symmetricallylocated or substantially equi-spaced—or both—around the centerbody 33and around the associated fluid-conduit housing 74, 74′, 142, 158. Inyet another set of embodiments, the plurality of radial pins 114, 222comprise at least three radial pins 114, 222.

Regarding the operation of the radial pins 114, 222, in one set ofembodiments, at least one the radial pin 114, 222 is slideably engagedwith both the corresponding radial bore 116, 228, 228.2 in the at leastone fluid-conduit housing 74, 74′, 142, 158 and the corresponding radialbore 118, 228, 228.1 in the centerbody 33.

In one set of embodiments, the radial pins 114, 222 are retained incooperation with both the centerbody 33 and the correspondingfluid-conduit housing 74, 74′, 142, 158, for example, by either stakingor welding 242 to the fluid-conduit housing 142, 158, by an interferencefit in the radial bore 228, 228.1, 228.2 in either the fluid-conduithousing 142, 158 or centerbody 33, or by engagement of a screw threadportion 236 of the radial pin 114, 222 with a corresponding screw threadportion in one of the fluid-conduit housing 142, 158 and the centerbody33.

For example, in one set of embodiments, the at least one bladed rotor30, 56 comprises at least one of the group selected from a bladedcompressor rotor 56 and a turbine rotor 30, for example, the compressorrotor 56 of a compressor 16 portion of a turbocharger assembly 200.2 ora compressor portion of a supercharger, and/or the turbine rotor 30 ofturbine 18 a turbocharger assembly 200.2.

At room temperature, a minimum tip clearance 212 between the shroudportion 82, 82′, 210 of the fluid-conduit housing 74, 74′, 142, 158 andat least one tip 120 of the at least one bladed rotor 30, 56 is lessthan 4 percent of a radius of the at least one bladed rotor 30, 56 atthe at least one tip 120 of the bladed rotor 30, 56 at a location ofminimum tip clearance 212 to the shroud portion 82, 82′, 210 of thefluid-conduit housing 74, 74′, 142, 158.

When incorporated in the turbine portion 18 of a turbocharger assembly200.2, the bladed rotor 30 comprises the turbine rotor 30 of theturbocharger assembly 200.2, the fluid-conduit housing 158 comprises anturbocharger exhaust housing 158 configured to receive exhaust gases 21from an internal combustion engine 14, 14.2, and a portion of theturbocharger exhaust housing 158 comprises the shroud portion 210 thatsubstantially concentrically surrounds the portion of the turbine rotor30. In one set of embodiments, the turbocharger exhaust housing 158comprises a volute portion 204 ^(i)′ of the fluid conduit 216 that isoperative between the inlet 160 and the turbine rotor 30, at least aportion of an aft boundary 206 ^(i) of the volute portion 204 ^(i)′comprises a surface of revolution 206 ^(i)′ about the axis of rotation202′ of the turbine rotor 30 where the fluid 21 is discharged from thevolute portion 204 ^(i)′ onto the turbine rotor 30 during operation ofthe turbocharger assembly 200.2, and the aft boundary 206 ^(i) islocated further from the centerbody 33 than a corresponding opposingforward boundary 207 ^(i) of the volute portion 204 ^(i)′. For example,in one embodiment the surface of revolution 206 ^(i)′ comprises a planarsurface that is substantially perpendicular to the axis of rotation 202.Each radial pin 222 being slideable in at least one of a correspondingradial bore 228 in the turbocharger exhaust housing 158 and acorresponding radial bore 228 in the centerbody 33 provides formaintaining the concentricity of the shroud portion 210 of theturbocharger exhaust housing 158 relative to the turbine rotor 30regardless of thermal expansion of the turbocharger exhaust housing 158relative to the centerbody 33, so that at room temperature, the tipclearance 212 between the shroud portion 210 of the turbocharger exhausthousing 158 and at least one tip 120 of the turbine rotor 30 at an aftportion thereof can be less than 4 percent of a radius of the turbinerotor 30 at the at least one tip 120 of the turbine rotor 30 at the aftportion thereof. A seal 246 operative between an end face 248 of theturbocharger exhaust housing 158 and the centerbody 33—for example,operative within a groove 250 in the end face 248 of the turbochargerexhaust housing 158—provides for preventing the exhaust gases 21 fromescaping the turbocharger exhaust housing 158 from a gap 234, 252between the turbocharger exhaust housing 158 and the centerbody 33,wherein the seal 246 is configured so as to provide for accommodatingthermal expansion or contraction of the turbocharger exhaust housing 158relative to the centerbody 33. For example, the seal 246 may compriseeither a thermal gasket 254, or a metallic seal 256, for example,comprising a radial cross-section selected from the group consisting ofa V-shaped cross-section 258 and a C-shaped cross-section 260. In oneset of embodiments, the external cylindrical surface 220 is stepped intothe corresponding side 33.1 of the centerbody 33, and the seal 246 isoperative between the end face 248 and a radial surface 262 extendingradially outwards from the external cylindrical surface 220 that isstepped into the corresponding side 33.1 of the centerbody 33. Inanother set of embodiments, a heat shield 266 is operative between thecenterbody 33 and the turbine rotor 30 within an axial bore 268 in theturbocharger exhaust housing 158, wherein the axial bore 268 has adiameter in excess of a maximum diameter of the turbine rotor 30.

When incorporated in the compressor portion 16 of a turbochargerassembly 200.2 or a supercharger, the at least one bladed rotor 56comprises the bladed compressor rotor 56 and the at least onefluid-conduit housing 142 comprises a compressor housing 142 surroundingthe compressor rotor 56, wherein the compressor housing 142 comprisescentral inlet 144 and a volute diffuser 146.

A method of operatively coupling a fluid-conduit housing 74, 74′, 142,158 to a centerbody 33 comprises:

-   -   a. sliding an internal cylindrical surface 110, 218 over a        corresponding external cylindrical surface 112, 220, wherein the        internal cylindrical surface 110, 218 is located at an end 158.2        of a fluid-conduit housing 74, 74′, 142, 158, and the external        cylindrical surface 112, 220 is located on a side 33.1 of a        centerbody 33;    -   b. operatively coupling the fluid-conduit housing 74, 74′, 142,        158 to the centerbody 33 using a plurality of radial pins 114,        222, wherein each radial pin 114, 222 of the plurality of radial        pins 114, 222 extends radially across a junction 224 between the        internal cylindrical surface 110, 218 and the external        cylindrical surface 112, 220, each the radial pin 114, 222        engages both the centerbody 33 and a wall 110, 226 of the        fluid-conduit housing 74, 74′, 142, 158 so as to prevent more        than insubstantial relative axial movement therebetween, and        each radial pin 114, 222 of the plurality of radial pins 114,        222 is slideably engaged with at least one of a corresponding        radial bore 228 in the fluid-conduit housing 74, 74′, 142, 158        and a corresponding radial bore 228 in the centerbody 33;    -   c. providing for retaining each the radial pin 114, 222 in        engagement with both the centerbody 33 and the wall 110, 226 of        the fluid-conduit housing 74, 74′, 142, 158; and    -   d. shrouding a portion of a bladed rotor 30 with a portion of        the fluid-conduit housing 74, 74′, 142, 158, wherein the bladed        rotor 30 is rotatable with respect to the centerbody 33 about an        axis 202′ that is substantially concentric with respect to the        external cylindrical surface 112, 220 and with respect to the        portion of the fluid-conduit housing 74, 74′, 142, 158 that        shrouds the bladed rotor 30.

In one set of embodiments, the method further comprises forming at leastone of the corresponding radial bore 116, 228, 228.2 in thefluid-conduit housing 74, 74′, 142, 158 and the corresponding radialbore 118, 228, 228.1 in the centerbody 33 after the operation of slidingthe internal cylindrical surface 110, 218 over the correspondingexternal cylindrical surface 112, 220.

In another set of embodiments, the method further comprising providing avolute portion 204 ^(i)′ of a fluid conduit 216 within the fluid-conduithousing 142, 158 that extends forward of an aft boundary 206 ^(i) of anoutlet 208 of the fluid conduit 216 onto the bladed rotor 30 so as toprovide for either a) a nominal direction of flow 264 of a fluid 21 ontoor from the bladed rotor 30 that is substantially radial, b) for flowonto the bladed rotor 30, a nominal direction of flow 264 of a fluid 21that is at least partially axially aftward relative to the centerbody 33with decreasing distance from the bladed rotor 30 or, c) for flow fromthe bladed rotor 30, a nominal direction of flow 264 of a fluid 21 thatis at least partially axially forward relative to the centerbody 33 withincreasing distance from the bladed rotor 30.

A method of operating a bladed rotor 30, 56 in cooperation with anassociated fluid-conduit housing 74, 74′, 142, 158, comprises

-   -   a. rotating a bladed rotor 30, 56 with a rotor shaft 32        rotationally supported from a centerbody 33;    -   b. concentrically surrounding a portion of the bladed rotor 30,        56 with a shroud portion 82, 82′, 210 of a fluid-conduit housing        74, 74′, 142, 158 that is radially separated from the bladed        rotor 30, 56 by an associated tip clearance 212; and    -   c. causing the fluid-conduit housing 74, 74′, 142, 158 to be        heated relative to the centerbody 33, thereby thermally        expanding the fluid-conduit housing 74, 74′, 142, 158 relative        to the centerbody 33 in a radial direction by action of a        plurality of radial pins 114, 222 operative between the        centerbody 33 and the fluid-conduit housing 74, 74′, 142, 158,        wherein the plurality of radial pins 114, 222 provide for        unrestrained relative radial movement of the fluid-conduit        housing 74, 74′, 142, 158 relative to the centerbody 33, the        plurality of radial pins 114, 222 provide for axially retaining        the fluid-conduit housing 74, 74′, 142, 158 against the        centerbody 33, and the plurality of radial pins 114, 222        provides for substantially maintaining a concentricity of the        shroud portion 82, 82′, 210 of the fluid-conduit housing 74,        74′, 142, 158 relative to the portion of the bladed rotor 30, 56        responsive to the operation of thermally expanding the        fluid-conduit housing 74, 74′, 142, 158.

In one set of embodiments, the fluid-conduit housing 158 comprises anturbocharger exhaust housing 158 of the turbocharger assembly 200.2, thebladed rotor 30 comprises a turbine rotor 30 of a turbocharger assembly200.2 driven by exhaust gases 21 of an internal combustion engine 14,14.2 directed through a portion of a fluid conduit 216 within theturbocharger exhaust housing 158 onto the turbine rotor 30, for example,through a volute 204 ^(i) in a region that extends forward of an aftboundary 206 ^(i) of an outlet 208 of the volute 204 ^(i) onto theturbine rotor 30 so as to provide for a direction of flow 264 of theexhaust gases 21 onto the turbine rotor 30 that is either substantiallyradially inwards or at least partially axially aftward from thecenterbody 33 with decreasing distance from the turbine rotor 30.

In another set of embodiments, the fluid-conduit housing 142 comprises acompressor housing 142 of a turbocharger assembly 200.2, and the bladedrotor 56 comprises a compressor rotor 56 of the turbocharger assembly200.2 that provides for compressing and pumping air into a portion of afluid conduit 216 within the compressor housing 142 and then into aninternal combustion engine 14, 14.2.

While specific embodiments have been described in detail in theforegoing detailed description and illustrated in the accompanyingdrawings, those with ordinary skill in the art will appreciate thatvarious modifications and alternatives to those details could bedeveloped in light of the overall teachings of the disclosure. It shouldbe understood, that any reference herein to the term “or” is intended tomean an “inclusive or” or what is also known as a “logical OR”, whereinwhen used as a logic statement, the expression “A or B” is true ifeither A or B is true, or if both A and B are true, and when used as alist of elements, the expression “A, B or C” is intended to include allcombinations of the elements recited in the expression, for example, anyof the elements selected from the group consisting of A, B, C, (A, B),(A, C), (B, C), and (A, B, C); and so on if additional elements arelisted. Furthermore, it should also be understood that the indefinitearticles “a” or “an” and the corresponding associated definite articles“the’ or “said”, are each intended to mean one or more unless otherwisestated, implied, or physically impossible. Yet further, it should beunderstood that the expressions “at least one of A and B, etc.”, “atleast one of A or B, etc.”, “selected from A and B, etc.” and “selectedfrom A or B, etc.” are each intended to mean either any recited elementindividually or any combination of two or more elements, for example,any of the elements from the group consisting of “A”, “B”, and “A AND Btogether”, etc. Yet further, it should be understood that theexpressions “one of A and B, etc.” and “one of A or B, etc.” are eachintended to mean any of the recited elements individually alone, forexample, either A alone or B alone, etc., but not A AND B together.Furthermore, it should also be understood that unless indicatedotherwise or unless physically impossible, that the above-describedembodiments and aspects can be used in combination with one another andare not mutually exclusive. Accordingly, the particular arrangementsdisclosed are meant to be illustrative only and not limiting as to thescope of the invention, which is to be given the full breadth of theappended claims, and any and all equivalents thereof.

1. An apparatus, comprising: a. a centerbody, wherein said centerbodycomprises: i. a bearing housing; ii. at least one bearing within andoperatively coupled to said bearing housing; and iii. a rotor shaftrotationally supported by said at least one bearing spaced along saidrotor shaft; b. at least one bladed rotor operatively coupled to saidrotor shaft supported by said centerbody; and c. at least onefluid-conduit housing in cooperation with said at least one bladedrotor, wherein said at least one bladed rotor is operative within acorresponding fluid conduit defined by said fluid-conduit housing, saidat least one fluid-conduit housing incorporates an inlet to provide forreceiving a corresponding fluid within said fluid conduit that providesfor either driving or being pumped by a corresponding said at least onebladed rotor responsive to an interaction of said corresponding fluidwith a plurality of blades of said at least one bladed rotor, said atleast one fluid-conduit housing comprises an internal cylindricalsurface at an end thereof that mates with a corresponding externalcylindrical surface on a corresponding side of said centerbody, an axisof said external cylindrical surface is substantially concentric with anaxis of rotation of said at least one bladed rotor and with an axis ofsaid internal cylindrical surface, said at least one fluid-conduithousing is operatively coupled to said centerbody with a plurality ofradial pins, so that said internal cylindrical surface is free tothermally expand relative to said external cylindrical surface, eachradial pin of said plurality of radial pins is slideably engaged with atleast one of a corresponding radial bore in said at least onefluid-conduit housing or a corresponding radial bore in said centerbody,said radial bore in said fluid-conduit housing is closed to said fluidconduit; each said radial pin is oriented radially with respect to bothsaid internal cylindrical surface and said external cylindrical surface,said plurality of radial pins are arranged around said centerbody so asto provide for said internal and external cylindrical surfaces to remainsubstantially concentric regardless of a thermal expansion of said atleast one fluid-conduit housing relative to said centerbody, and atleast a portion of said at least one fluid-conduit housing comprises ashroud portion that substantially concentrically surrounds a portion ofsaid at least one bladed rotor.
 2. A apparatus as recited in claim 1,wherein said at least one bladed rotor comprises at least one of thegroup selected from a compressor rotor and a turbine rotor.
 3. Aapparatus as recited in claim 1, wherein said internal and externalcylindrical surfaces are mated with an interference fit at roomtemperature.
 4. A apparatus as recited in claim 1, wherein saidplurality of radial pins are symmetrically located around saidcenterbody and around said at least one fluid-conduit housing.
 5. Aapparatus as recited in claim 1, wherein said plurality of radial pinsare equi-spaced around said centerbody and around said at least onefluid-conduit housing.
 6. A apparatus as recited in claim 1, whereinsaid plurality of radial pins comprise at least three radial pins.
 7. Aapparatus as recited in claim 1, wherein at least one said radial pin isslideably engaged with both said corresponding radial bore in said atleast one fluid-conduit housing and said corresponding radial bore insaid centerbody, and at least one said radial pin is retained to said atleast one fluid-conduit housing by either staking or welding.
 8. Aapparatus as recited in claim 1, wherein at least one said radial pin isretained to said at least one fluid-conduit housing by an interferencefit in said radial bore in said at least one fluid-conduit housing.
 9. Aapparatus as recited in claim 1, wherein at least one said radial pin isretained by engagement of a screw thread portion of at least one saidradial pin with a corresponding screw thread portion in one of said atleast one fluid-conduit housing and said centerbody.
 10. A apparatus asrecited in claim 2, wherein said at least one bladed rotor comprisessaid turbine rotor of a turbocharger, said fluid-conduit housingcomprises an exhaust housing configured to receive exhaust gases from aninternal combustion engine, and a portion of said exhaust housingcomprises said shroud portion that substantially concentricallysurrounds said portion of said turbine rotor.
 11. A apparatus as recitedin claim 10, wherein said exhaust housing comprises a volute portion ofsaid fluid conduit that is operative between said inlet and said turbinerotor, an aft boundary of said volute portion comprises a surface ofrevolution about said axis of rotation of said turbine rotor where saidfluid is discharged from said volute portion onto said turbine rotorduring operation of said turbocharger, and said aft boundary is locatedfurther from said centerbody than a corresponding opposing forwardboundary of said volute portion.
 12. A apparatus as recited in claim 11,wherein said surface of revolution comprises a planar surface that issubstantially perpendicular to said axis of rotation.
 13. A apparatus asrecited in claim 10, wherein a tip clearance between said shroud portionof said exhaust housing and at least one tip of said turbine rotor isless than 4 percent of a radius of said turbine rotor at said at leastone tip of said turbine rotor at room temperature.
 14. A apparatus asrecited in claim 10, further comprising a seal operative between an endface of said exhaust housing and said centerbody, so as to provide forpreventing said exhaust gases from escaping said exhaust housing from agap between said exhaust housing and said centerbody, wherein said sealis configured so as to provide for accommodating thermal expansion orcontraction of said exhaust housing relative to said centerbody.
 15. Aapparatus as recited in claim 14, wherein said seal is operative withina groove in said end face of said exhaust housing.
 16. A apparatus asrecited in claim 15, wherein said seal comprises a thermal gasket.
 17. Aapparatus as recited in claim 15, wherein said seal comprises a metallicseal comprising a radial cross-section selected from the groupconsisting of a V-shaped cross-section and a C-shaped cross-section. 18.A apparatus as recited in claim 14, wherein said external cylindricalsurface is stepped into said corresponding side of said centerbody, andsaid seal is operative between said end face and a radial surfaceextending radially outwards from said external cylindrical surface thatis stepped into said corresponding side of said centerbody.
 19. Aapparatus as recited in claim 10, further comprising a heat shieldoperative between said centerbody and said turbine rotor within an axialbore wherein said exhaust housing, wherein said axial bore has adiameter in excess of a maximum diameter of said turbine rotor.
 20. Aapparatus as recited in claim 2, wherein said at least one bladed rotorcomprises said compressor rotor of a turbocharger, and said at least onefluid-conduit housing comprises a compressor housing surrounding saidcompressor rotor, wherein said compressor housing comprises: a. acentral inlet; and b. a volute diffuser.
 21. A method of operativelycoupling a fluid-conduit housing to a centerbody, comprising: a. slidingan internal cylindrical surface over a corresponding externalcylindrical surface, wherein said internal cylindrical surface islocated at an end of a fluid-conduit housing, and said externalcylindrical surface is located on a side of a centerbody; b. operativelycoupling said fluid-conduit housing to said centerbody using a pluralityof radial pins, wherein each radial pin of said plurality of radial pinsextends radially across a junction between said internal cylindricalsurface and said external cylindrical surface, each said radial pinengages both said centerbody and a wall of said fluid-conduit housing soas to prevent more than insubstantial relative axial movementtherebetween, and each radial pin of said plurality of radial pins isslideably engaged with at least one of a corresponding radial bore insaid fluid-conduit housing or a corresponding radial bore in saidcenterbody; c. providing for retaining each said radial pin inengagement with both said centerbody and said wall of said fluid-conduithousing; and d. shrouding a portion of a bladed rotor with a portion ofsaid fluid-conduit housing, wherein said bladed rotor is rotatable withrespect to said centerbody about an axis that is substantiallyconcentric with respect to said external cylindrical surface and withrespect to said portion of said fluid-conduit housing that shrouds saidbladed rotor.
 22. A method of operatively coupling a fluid-conduithousing to a centerbody as recited in claim 21, wherein at roomtemperature a diameter of said corresponding external cylindricalsurface exceeds a corresponding diameter of said internal cylindricalsurface so as to provide for an interference fit therebetween when bothsaid centerbody and said fluid-conduit housing are at said roomtemperature.
 23. A method of operatively coupling a fluid-conduithousing to a centerbody as recited in claim 21, further comprisingforming at least one of said corresponding radial bore in saidfluid-conduit housing or said corresponding radial bore in saidcenterbody after the operation of sliding said internal cylindricalsurface over said corresponding external cylindrical surface.
 24. Amethod of operatively coupling a fluid-conduit housing to a centerbodyas recited in claim 21, further comprising slideably engaging at leastone said radial pin with both said corresponding radial bore in saidfluid-conduit housing and said corresponding radial bore in saidcenterbody.
 25. A method of operatively coupling a fluid-conduit housingto a centerbody as recited in claim 21, further comprising retaining atleast one said radial pin is retained to said fluid-conduit housing byeither staking or welding.
 26. A method of operatively coupling afluid-conduit housing to a centerbody as recited in claim 21, furthercomprising retaining at least one said radial pin is retained to saidfluid-conduit housing by an interference fit in said radial bore in saidfluid-conduit housing.
 27. A method of operatively coupling afluid-conduit housing to a centerbody as recited in claim 21, furthercomprising retaining at least one said radial pin by engaging a screwthread portion of at least one said radial pin with a correspondingscrew thread portion in one of said fluid-conduit housing and saidcenterbody.
 28. A method of operatively coupling a fluid-conduit housingto a centerbody as recited in claim 21, further comprising installing aheat shield operative between a portion of said side of said centerbodyand said bladed rotor, wherein said heat shield provides forsubstantially filling an annulus located between a portion of saidcenterbody proximate to said bladed rotor and an axial bore in saidfluid-conduit housing that provides for receiving said bladed rotortherethrough during the operation of sliding said internal cylindricalsurface of said fluid-conduit housing over said corresponding externalcylindrical surface of said centerbody.
 29. A method of operativelycoupling a fluid-conduit housing to a centerbody as recited in claim 21,further comprising providing a volute portion of a fluid conduit withinsaid fluid-conduit housing that extends forward of an aft boundary of anoutlet of said fluid conduit onto said bladed rotor so as to provide fora direction of flow of a fluid onto or from said bladed rotor that iseither substantially radially inwards or at least partially axiallyaftwards from said centerbody with decreasing distance from said bladedrotor.
 30. A method of operatively coupling a fluid-conduit housing to acenterbody as recited in claim 21, further comprising sealing a gapbetween a portion of an end face of said fluid-conduit housing and aportion of said side of said centerbody, wherein the operation ofsealing said gap provides for relative radial movement of said portionof said end face of said fluid-conduit housing relative to saidcenterbody responsive to a thermal expansion of said fluid-conduithousing.
 31. A method of operating a bladed rotor in cooperation with anassociated fluid-conduit housing, comprising: a. rotating a bladed rotorwith a rotor shaft rotationally supported from a centerbody; b.concentrically surrounding a portion of said bladed rotor with a shroudportion of a fluid-conduit housing that is radially separated from saidbladed rotor by an associated tip clearance; and c. causing saidfluid-conduit housing to be heated relative to said centerbody, therebythermally expanding said fluid-conduit housing relative to saidcenterbody in a radial direction by action of a plurality of radial pinsoperative between said centerbody and said fluid-conduit housing,wherein said plurality of radial pins provide for unrestrained relativeradial movement of said fluid-conduit housing relative to saidcenterbody, said plurality of radial pins provide for axially retainingsaid fluid-conduit housing against said centerbody, and said pluralityof radial pins provides for substantially maintaining a concentricity ofsaid shroud portion of said fluid-conduit housing relative to saidportion of said bladed rotor responsive to the operation of thermallyexpanding said fluid-conduit housing.
 32. A method of operating a bladedrotor in cooperation with an associated fluid-conduit housing as recitedin claim 31, wherein said fluid-conduit housing comprises an exhausthousing of a turbocharger, and said bladed rotor comprises a turbinerotor of said turbocharger driven by exhaust gases of an internalcombustion engine directed through a portion of a fluid conduit withinsaid exhaust housing onto said turbine rotor.
 33. A method of operatinga bladed rotor in cooperation with an associated fluid-conduit housingas recited in claim 32, wherein said portion of said fluid conduitcomprises a volute, further comprising causing said exhaust gases toflow within said volute in a region that extends forward of an aftboundary of an outlet of said volute onto said turbine rotor so as toprovide for a direction of flow of said exhaust gases onto said turbinerotor that is either substantially radially inwards or at leastpartially axially aftwards from said centerbody with decreasing distancefrom said turbine rotor.
 34. A method of operating a bladed rotor incooperation with an associated fluid-conduit housing as recited in claim31, wherein said fluid-conduit housing comprises a compressor housing ofa turbocharger, and said bladed rotor comprises a compressor rotor ofsaid turbocharger that provides for compressing and pumping air into aportion of a fluid conduit within said compressor housing and then intoan internal combustion engine.
 35. A method of operating a bladed rotorin cooperation with an associated fluid-conduit housing as recited inclaim 31, further comprising sealing a gap between a portion of an endface of said fluid-conduit housing and a portion of said side of saidcenterbody, wherein the operation of sealing said gap provides forrelative radial movement of said portion of said end face of saidfluid-conduit housing relative to said centerbody responsive to athermal expansion of said fluid-conduit housing.